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Chris Zankel9a8fd552005-06-23 22:01:26 -07001/*
2 * include/asm-xtensa/delay.h
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 2001 - 2005 Tensilica Inc.
9 *
10 */
11
12#ifndef _XTENSA_DELAY_H
13#define _XTENSA_DELAY_H
14
Chris Zankel9a8fd552005-06-23 22:01:26 -070015#include <asm/processor.h>
16#include <asm/param.h>
17
18extern unsigned long loops_per_jiffy;
19
Adrian Bunkd99cf712005-09-03 15:57:53 -070020static inline void __delay(unsigned long loops)
Chris Zankel9a8fd552005-06-23 22:01:26 -070021{
Chris Zankelc4c45942012-11-28 16:53:51 -080022 /* 2 cycles per loop. */
23 __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b"
24 : "=r" (loops) : "0" (loops));
Chris Zankel9a8fd552005-06-23 22:01:26 -070025}
26
27static __inline__ u32 xtensa_get_ccount(void)
28{
29 u32 ccount;
Max Filippovbc5378f2012-10-15 03:55:38 +040030 asm volatile ("rsr %0, ccount\n" : "=r" (ccount));
Chris Zankel9a8fd552005-06-23 22:01:26 -070031 return ccount;
32}
33
34/* For SMP/NUMA systems, change boot_cpu_data to something like
35 * local_cpu_data->... where local_cpu_data points to the current
36 * cpu. */
37
38static __inline__ void udelay (unsigned long usecs)
39{
40 unsigned long start = xtensa_get_ccount();
41 unsigned long cycles = usecs * (loops_per_jiffy / (1000000UL / HZ));
42
43 /* Note: all variables are unsigned (can wrap around)! */
44 while (((unsigned long)xtensa_get_ccount()) - start < cycles)
45 ;
46}
47
48#endif